Antibodies to various antigens have been a common diagnostic tool used by research labs in modern times. Any molecule, particle, hormone, bacteria, etc. of interest in research setting requires tracking. A simple method of tracking a particle of interest is the development antibodies to that particle. Antibodies may be labelled with enzymes and used in diagnostic tests, such as ELISA, to qualitatively or quantitatively track particles in a given sample.
Mammals are frequently the animals of choice for producing tracking antibodies as they are common, well known to those practiced in the art. While the amounts of antibody obtained from mammals are usually small they are usually sufficient for research purposes. Avian eggs, specifically from domestic chickens, have also been used to produce antibodies for research purposes. There are some advantages to using avian antibodies which include larger amounts and lower background cross-reactions with research samples. Avian antibodies used for research and other purposes are invariably egg yolk antibodies known as IgY.
The advantages and disadvantages of IgY over mammalian antibodies for research and tracking purposes is well known to those practiced in the art:                1. IgY as a single class of antibody is present in only the egg yolk while mammalian antibody classes are all mixed together in serum. The natural segregation of a single antibody class in the egg yolk makes isolation of the single antibody easy in comparison to processing serum to obtain a single mammalian antibody class.        2. Cross-reactions are a major complication in any antibody based diagnostic test. If Mammalian antibodies are used for research in mammalian systems, researchers run the risk of false positive results from activation of the complement system, activation of the clotting cascade and interference with rheumatoid factor. IgY antibodies do not have these cross-reactions in mammalian systems.        3. Chicken IgY antibodies may be freeze dried with little or no loss in functionality. Mammalian antibodies lose a great deal of their activity after freeze drying.        4. Production of egg antibodies from chicken eggs is inherently safe. Eggs are generally regarded as safe, and isolating IgY antibodies from egg yolk involved neither needles nor hazardous chemicals. Mammals must be bled on a regular basis using needles and exposure to blood products is virtually assured.        
Avian IgA and IgM antibodies are known to be present only in the white portion of chicken eggs, just as IgY is known to be present only in the egg yolk. Multiple mentions of egg white IgA and IgM have been made in the literature, but only with regard to their existence as antibodies produced by the avian immune system or to the small amounts present in the white relative to the much more plentiful IgY in the yolk (Rose and Orlans, 1981). Since IgA and IgM in egg white are present in much smaller absolute amounts than IgY in the yolk, only IgY has been explored as a useful product on a commercial scale in either research and clinical diagnostics fields or health care fields.
A discussion of chicken immunology shows that immunization and subsequent boosting with a given immunogen gives rise to the multiple class of antibodies in eggs, IgM, IgA and IgY each specific to said immunogen (Kincade and Cooper, 1971; Martin and Leslie, 1974). Isotype switching shows that the portions of the antibodies, or binding sites, specific to a given immunogen are exactly the same in all classes of antibodies, IgM, IgA and IgY and are produced by the same B-lymphocytes.
The molecular structure of chicken antibodies have been studied and reviewed in Avian Immunology (2008, p. 109). IgM is characterized by a molecular weight of 823-954 kDa; the H chain has MW of ˜70 kDa and the L chain has a MW of 22 kDa. IgA is characterized by a molecular size of 16.2 S.
IgA has been recognized as the first and best line of defense in avians, but commercial amounts of IgA are not readily available.
There is no publicly known procedure for commercial scale isolation of IgA and IgM antibodies from the egg whites of domestic chickens prior to this invention. Given the known advantages of using IgY from egg yolks, exploring the commercial scale advantages of IgA and IgM is desirable.